Process of preparing silvering liquid.



Units Starts PATENT "FFlQE.

CONSTANT LAVAL, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO J.W. PETERS AND G. M. SUTER, OF SAME PLACE.

PROCESS OF PREPARING SILVERING LIQUID.

SPECIFICATION forming part of Letters Patent No. 670,156, dated March19, 1901.

Application filed March 6, 1900.

To (LZZ whom, it may concern.-

Be it known that I, CONSTANT LAVAL, a citizen of the United States,residing at Allegheny, in the county of Allegheny and State ofPennsylvania, have invented new and useful Improvements in Processes ofPreparing a Silvering Liquid, of which the following is a specification.

My invention relates to a process of preparing a liquid for silveringglass, the.

It is the main object of my invention to provide a silvering liquidadapted for convenient application for silvering bulbs of incandescentelectric lights, so that a portion of said bulbs shall act as areflector.

In practice I have found that the ordinary silvering preparations cannotbe successfully employed for this purpose, as they will not withstandthe heat and will either peel off or tarnish his the aim, therefore, ofmyinvention to provide a silvering liquid which when applied to anddeposited upon the glass bulbs of incandescent lights will furnish abrilliant reflecting-surface and one which will not tarnish or peel offunder a high degree of heat or be injuriously affected by cold ordampness. Applications of the liquid for silvering articles other thanglass bulbs are of course contemplated.

My improved silvering liquid is prepared and used in thefollowing-described manner: I first dissolve fifty grains of nitrate ofsilver in eight ounces of distilled water and then add one ounce and ahalf of concentrated ammonia having a strength of twentysix per cent.This mixture is well shaken and filtered and forms what I will termsolution No. 1. In a suitable receptacle I next dissolve fifty grams ofpotassium and sodium tartrate in eight ounces of distilled water. This Iterm mixture A. In another receptacle twenty grams of powdered nickelsesquioxid are mixed in four ounces of filtered water. ThisI termmixture B. Mixtures A and B are then poured into an evaporating-pan,which is placed on any suitable heating apparatus. The mixture is thenstirred until it has been brought to the boiling-point or until a thinfilm has formed on the surface of the liquid, after which it is SerialNo. 7,548. (Specimens) cooled and filtered. This forms what I will termsolution No. 2.

' When the above-described preparations are to be used, I mix one ounceof solution No. l and one ounce of solution No. 2 with sixteen ounces ofdistilled water, thereby forming the silvering liquid, which must beused im mediately.

In proceeding to apply the silvering liquid the glass bulb or otherglass article is first cleansed by rubbing its surface with a wet bagcontaining powdered sulfate of iron, after which the glass article isheld under running water and rubbed with a brush until it is free of thesulfate of iron and then rinsed off in distilled water. The silveringliquid may now be poured on the bulb, and it will be found that themetal will instantaneously deposit on the glass. A porcelain dish may beemployed to catch the liquid, and the same liquid may be poured over thebulb several times until the latter has acquired a uniform coating.YVhen dry, the portion of the deposit that I desire to remain on thebulb is coated with a mixture of aluminium powder and crystallinevarnish or liquid celluloid. WVhen this coating has dried, the remainderof the deposit may be removed from the bulb by means of pumice-stone.

The nickel sesquioxid, in conjunction with the potassium and sodiumtartrate, acts as a reactionary agent to deposit the silver on the glassand causes a strong adherence of the same thereto.

In proceeding to apply the silvering liquid or mixture to a glass bulb,globe, or other glass article the said article must be first cleaned andrinsed ofi before mixing the solutions 1 and 2, and as soon as the saidsolutions 1 and 2 are mixed the liquid must be poured over the bulb orother glass article, as it takes less than a minute for solution No. 2to react on solution No.1 and cause the metals to deposit. The mixtureof silver and nickel makes a more adherent and hard coating than can beobtained with silver alone.

What I claim as my invention is l. The process of preparing a silveringliquid, which consists in mixing nitrate of silver, water and ammoniaand filtering the oxid and boiling and filtering the same; and finallymixing equal parts of the filtered solutions with Water, immediatelybefore applying said liquid to the article to be silverecl.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CONSTANT LAVAL.

Witnesses:

J. W. PETERS, O. M. SUTER.

